High voltage disconnect electric circuit interrupter



March 23, 1965 H. H. SCHWAGER ETAL 3,175,054

HIGH VOLTAGE DISCONNECT ELECTRIC CIRCUIT INTERRUPTER Filed Oct. 15, 1962 2 Sheets-Sheet l llmhh n Henry H. Schwager C bar/es E. Kerr 1N VEN TORS March 23, 1965 H. SCHWAGER T 3,175,054

HIGH VOLTAGE DISCONNECT ELECTRIC CIRCUIT INTERRUPTER 2 Sheets-Sheet 2 Filed 001;. 15, 1962 WWW .H

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United States Patent 3,175,054 HIGH VOLTAGE DECQNNECT ELECTRBC CIRCUIT HNTERRUPTER Henry H. Schwager, Portland, and Charles E, Kerr, Hillsboro, Greg, assignors to Powerdyne, Inc, Lake Uswego, Greg, a corporation of Oregon Filed Oct. 15, 1962, Ser. No. 230,413 10 Claims. ((31. 200-48) This invention relates to electric circuit interrupters and, in particular, to an interrupter for use with conventional outdoor air break disconnecting switches for interrupting electric currents of substantial magnitudes.

Although interrupters of the class described have been provided heretofore, they have not been completely satisfactory because of one or more of the following primary disadvantages: Some of them are characterized by rather complex construction which contributes to inconsistent operation and requires excessive maintenance and repair. Some have been characterized by unsatisfactory operation under conditions of icing. Some have been limited to rather low current systems because of their characteristic slow speed of contact separation. And some have been characterized by excessive arcing due to contact rebound during opening.

It is the principal object of the present invention to overcome the aforementioned disadvantages by providing an electric circuit interrupter which is of simplified construction for economical manufacture and maintenance, which operates with consistent precision even under adverse conditions of heavy icing, and in which contact rebound during opening is substantially eliminated.

Other objects and advantages attained through the medium of the present invention will become apparent from the following detailed description in which reference is made to the accompanying drawings.

In the drawings:

FIG. 1 is a fragmentary view in side elevation of a conventional air break disconnect switch having associated therewith an interrupter embodying the features of the present invention;

FIG. 2 is a fragmentary sectional view taken along the line 22 in FIG. 1;

*FIG. 3 is a fragmentary plan view as viewed in the direc tion of the arrows 3-3 in FIG. 1;

FIG. 4 is a foreshortened, partially sectioned view of the interrupter, showing the assembly in retracted condition;

FIG. 5 is a foreshortened partially sectioned view as viewed trom the bottom in FIG. 4; and

FIG. 6 is a fragmentary, partially sectioned view similar to FIG. 5 and showing a portion of the assembly in extended condition.

Referring particularly to FIG. 1 of the drawings, the conventional air break disconnect switch illustrated therein includes a base 10 which supports the vertically extending insulators 12, 14 and 16. Supported between the insulators 14 and 16 is the mounting base 18 for the main switch blade 29. The main switch blade is mounted pivotally on the axis 22 for movement between the closed position illustrated in full lines, and the open condition illustrated in dashed lines. It is also mounted for rotation on its longitudinal axis, for example through an arc of about 30, during said opening and closin movement.

These movements are effected by rotation of the vertical shaft 24 extending through the insulator 14. Rotation of this shaft, either by a manually operable lever 26 or by appropriate power means, effects rotation of the connected arm 28 which, in turn, effects longitudinal movement and partial axial rotation of the link 39 which interconnects the arm 28 and the switch blade 20 at the respective pivots 32 and 34.

The outer end of the main switch blade 20 enters between a pair of spaced contacts 36 extending from the base 36' mounted on insulator 12. The blade makes firm engagement with the contacts by said axial rotation of the blade. Upon disengagement and during pivotal movement upwardly away from the spaced contacts, the main blade slidably engages the arcing born 38 which serves to prevent arcing at the contacts 36. The horn projects from a base 38 mounted on insulator 12 in electrical contact with base 35'.

Installation of the foregoing mechanism in an electric circuit is made by means of the connectors: 40 and 42 at the mounting base 18 and contact 36, respectively.

The foregoing assembly is of Well known construction, and forms no part of the present invention. -It is shown herein merely to illustrate one form of conventional disconnecting switch with which the interrupter of the present invention may be utilized.

The interrupter includes an elongated hollow housing 44. of electric-ally conductive material. The housing is mounted removably on the main switch blade 20, substantially parallel thereto, by such means as the clamping brackets 46 which atford rotational adjustment of the housing as well as longitudinal adjustment relative to the main switch blade.

Adjacent the forward open end of the housing is a transverse wall 4-8 FIGS. 4 and 5), secured within the housing by such means as the screws 50. Laterally spaced cars 52 project forwardly from the wall and support between them the pivot pin 54. This pivot pin, in turn, supports the pulley 56 and the laterally spaced ears 58 projecting rearwardly from the plate 60 which supports the resilient bumper 62.

A rearward extension 64 on the transverse wall 48 (FIG. 4) receives the pin 66 which mounts the forward ends of a pair of laterally spaced plates 68, the rearward ends of which are interconnected by the transverse pin '70. A pair pulleys '72, 74 are positioned between the plates, intermediate the ends of the latter, and mounted for rotation on the transverse shaft '76.

The rearward end of the housing is closed by the cap 78 (FIGS. 4 and 5). Extending forwardly from the cap is an anchor rod 80 provided at its forward end with a hook which engages the rearward hook end of an elongated coil spring 82. The forward hook end of the spring engages the transverse pin 84 supported at the rearward end of a floating pulley frame which includes the transversely spaced plates 86 and the forward interconnecting pin 88. A transverse shaft 90 is supported by the plates 86, intermediate the ends of the latter, and the shaft, in turn, supports the three pulleys 2, 94 and 95.

The inner end 98 of an electrically conductive cable Hill is secured to the forward wall 48. It then is reeved successively over the pulleys 92, '74, 94, 72, 96 and then fed outwardly through an opening 192 in the forward wall 43 and an opening 104 in the plate 60 and bumper 62. The outer end of the cable 106 is secured to an electrically conductive terminal plug 106 provided at its inner end with an enlarged seat 1% for abutting the bumper 62, and at its outer end with an enlarged head lit The cable lllil normally is maintained retracted within the housing 44 by contraction of the coil spring 82, whereby to maintain the terminal plug in abutment with the bumper 62.

The plug 1% may be pulled away from the bumper, against the tension of the spring 82. This poistion of retraction is determined by a length of cable 112 interconnecting the pins 70 and lid. The length of this cable is chosen such that it becomes taut just as the seat 103 of the plug 106 engages the bumper 62. In order to minimize the force of abutment, the inner end portion of the cable 100 is held resiliently in a slackened condition by means of the short length of cable 114 and coil spring 116.

The plug 106 may be pulled away from the bumper, against the tension of the spring 32, thereby extending the cable 100 from the housing 44. The length of extension is determined by a length of cable 118 (FIG. 4) which extends rearwardly from the pin 84 supported by the floated pulley frame, to an anchor block 120. This block is provided with a longitudinal opening which slidably receives the anchor rod 80 therethrough, and is also provided with the tapped bore which receives the threaded adjustment rod 122 mounted for rotation in the rear cap 78. In the retracted position of the cable 100 illustrated in FIGS. 4 and 5, the stop cable 118 is slack, and will become taut when the plug 106 is pulled from the bumper 62 to a predetermined distance. Variations from this distance may be adjusted by means of the threaded rod 122.

The terminal plug 106 is adapted for releasable attachment toa retaining horn which, in the embodiment illustrated, is mounted upon the same terminal block 38' as the main arcing horn 38 (FIGS. 1 and 2). The retaining horn comprises a pair of electrically conductive rods each of which is bent to a generally U-shape, as viewed in FIG. 1, providing a forward arm 124 and a rearward arm 126 interconnected at their upper ends by the intermediate section 128. The two rods are mounted with their forward arms 124 extending upward from the mounting block 38', and with the intermediate sections 128 disposed closely adjacent each other. The rearward arms 126 diverge downwardly from the intermediate sections, as best shown in FIG. 2.

The retaining horn is so mounted in relation to the main switch blade that the head 110 of the retracted plug is in the position shown in FIGS. 1 and 2 when the main switch blade has been rotated (counterclockwise) the exemplified necessary for release from the spaced contacts 36, preparatory to opening of the blade. Then, as the main switch blade swings upward, as indicated in FIG. 1, the plug moves upwardly between the converging arms 126 of the retaining horn until the intermediate reduced stem of the plug 106 is forced between the adjacent intermediate sections 128 of the born, with the enlarged head 110 of the plug underlying the said intermediate sections. The upper end of the retaining horn terminates below the upper end of the main arcing horn 38, to insure positive engagement of the plug with the retaining horn before the main switch blade leaves its arcing horn.

Upon further upward movement of the main switch blade 20 the cable 100 attached to the plug 106 is drawn outwardly from the housing 44- through the opening 105 in the bumper 62 and its supporting plate 60. As best shown in FIG. 6, this assembly (including the bumper 62 and plate 60) pivots on the pin 54 to permit maintenance of the bumper normal to the extending cable, and the latter is guided over the forward pulley 56 as the bumper assembly is pivoted.

Continued upward movement of the main switch blade effects further extension of the cable 100 until the stop cable 118 becomes taut. The enlarged head 110 of the plug thereupon is caused to be pulled free of the retaining horn by spreading the intermediate sections 128. The force required to pull this head through the horn may be varied by the adjustment block 130 (FIG. 2) which connects the forward rods 124 and which may be adjusted vertically along the rods to vary the spacing between the intermediate sections 128.

Having pulled the plug head 110 free of the retaining horn, the spring 82 within the housing 44 immediately contracts, drawing the floating pulley assembly rearward and rapidly retracting the extended length of cable 100 until the seat 108 of the plug is drawn into abutment with. the bumper 62. The latter then pivots clockwise on the pin 54, returning to the position shown in FIGS. 4 and 5, wherein the projection 132 on the car 53 abuts the end of the ear 52.

Retraction of the interrupter cable is extremely fast and positive. The terminal plug head 110 is pulled through the retaining horn with a minimum of force, thus minimizing the power requirement for opening the main switch blade 20, either by hand or by a power motor. Moreover, this minimizing of the power requirement for retraction of the plug from the retaining horn also substantially eliminates whip or rebound of the main switch blade toward its contacts 36, thereby eliminating the possibility of reestablishing an arc therebetween.

In returning the main switch blade 20 toward the closed position, the terminal plug 106 projecting from the bumper 62 engages the outer sides intermediate of the sections 128 of the retaining horn, and slides downward along the rearward diverging sides of the rods 124 while simultaneously being tipped at an angle with respect to the bumper, until it reaches a downward position where it can enter the space between the diverging rods. The plug then snaps back to its normal position of extension from the bumper. The switch blade 20 then may be rotated clockwise through the 30 indicated in FIG. 2, into firm engagement with the spaced contacts 36.

The relative lengths of the housing 44 and the components retained therein, as well as the number of pulleys, may be varied over a wide range to provide any desired length of extension of the cable 100. As an illustration, the interrupter assembly may be proportioned to provide a cable extension of 30 inches, and the adjustment screw 122 may accommodate varying the length of extension by plus or minus 6 inches, i.e. between 24 inches and 36 inches. The 30 inch cable extension accommodates the disconnecting of 230,000 volts, and therefore it will be understood that variations in this length of extension may be made to accommodate the switching of other magnitudes of potential.

Various modifications may be made in the details of construction described hereinbefore, without departing from the principle or scope of the invention, and it is not intended to restrict the invention exactly to the construction shown, which is shown only as a preferred example, or to limit the invention otherwise than as set forth in the claims.

We claim:

1. For use with an electric circuit breaker having a blade member movable relative to a contact member: an interrupter comprising a cable support means, mounting means adapted to mount the support means firmly on the blade member for movement therewith, an elongated electrically conductive cable mounted on the support for extension and retraction relative to the latter, electrically conductive means operatively engaging the cable and adapted for engaging the blade member for electrically interconnecting the cable and blade member, resilient means operatively interengaging the cable and support for urging the cable in the retracting direction, electrically conductive terminal means on the extendable end of the cable, and electrically conductive retainer means adapted for mounting in electrically conductive relation with the contact member and arranged to retain the terminal means releasably against a predetermined pulling force of the cable.

2. The interrupter of claim 1 wherein the terminal means comprises a headed plug and the retainer means comprises resilient gripping means for releasably retaining the headed plug.

3. The interrupter of claim 1 wherein the cable support includes an electrically conductive elongated housing for the cable, and the resilient means comprises an elongated spring within the housing operatively interconnecting the cable and housing, the housing having an opening for passage of the cable therethrough.

4. The interrupter of claim 3 including bumper means mounted pivotally on the housing and engageable by the cable to maintain the bumper substantially normal to the cable for arresting the retractive movement of the terminal means.

5. For use with an electric circuit breaker having a lade member movable relative to a contact member: an interrupter comprising an electrically conductive elongated housing, electrically conductive clamp means on the housing and adapted for attachment to the blade member for mounting the housing firmly on the blade member for movement therewith, an elongated electrically conductive cable engaging the housing electrically and mounted in the housing for extension and retraction relative to the housing, an elongated spring within the housing operatively interconnecting the cable and housing for urging the cable in the retracting direction, bumper means mounted pivotally on the housing and having an opening freely receiving the cable therethrough, electrically conductive terminal means on the extendable end of the cable and having a seat end normally abutting the bumper means in the retracted condition of the cable, the terminal means also having a headed end, and electrically conductive resilient gripping means adapted for mounting in electrically conductive relation with the contact member and arranged for releasably retaining the headed end of the terminal means releasably against a predetermined pulling force of the cable.

6. In combination with an electric circuit breaker having a blade member movable relative to a contact member: an interrupter comprising a cable support mounted firmly on the blade member for movement therewith, an elongated electrically conductive cable engaging the blade member electrically and mounted on the support for extension and retraction relative to the latter, resilient means operatively interengaging the cable and support for urging the cable in the retracting direction, electrically conductive terminal means on the extendable end of the cable, and electrically conductive retainer means mounted in electrically conductive relation with the contact member and arranged to retain the terminal means releasably against a predetermined pulling force of the cable.

7. The combination of claim 6 wherein the terminal means comprises a headed plug and the retainer means comprises resilient gripping means for releasably retaining the headed plug.

8. The combination of claim 6 wherein the cable sup port includes an electrically conductive elongated housing for the cable, and the resilient means comprises an elongated spring Within the housing operatively interconnecting the cable and housing, the housing having an opening for passage of the cable therethrough.

9. The combination of claim 8 including bumper means mounted pivotally on the housing and engageable by the cable to maintain the bumper substantially normal to the cable for arresting the retractive movement of the terminal means.

10. In combination with an electric circuit breaker having a blade member movable relative to a contact member: an interrupter comprising an electrically conductive elongated housing mounted on the blade memher, an elongated electrically conductive cable engaging the housing electrically and mounted in the housing for extension and retraction relative to the housing, an elongated spring Within the housing operatively interconnecting the cable and housing for urging the cable in the retracting direction, bumper means mounted pivotally on the housing and having an opening freely receiving the cable therethrough, electrically conductive terminal means on the extendable end of the cable and having a seat end normally abutting the bumper means in the retracted condition of the cable, the terminal means also having a headed end, and electrically conductive resilient gripping means mounted in electrically conductive relation with the contact member and arranged for retaining the headed end of the terminal means releasably against a predetermined pulling force of the cable.

References Cited by the Examiner UNITED STATES PATENTS 2,112,071 3/38 Crabbs 200-48 2,785,254 3/57 Atkinson W 200-62 X FOREIGN PATENTS 1,077,293 3/60 Germany. 113,617 3/45 Sweden.

ROBERT K. SCHAEFER, Acting Primary Examiner. 

1. FOR USE WITH AN ELECTRIC CIRCUIT BREAKER HAVING A BLADE MEMBER MOVABLE RELATIVE TO A CONTACT MEMBER: AN INTERRUPTER COMPRISING A CABLE SUPPORT MEANS, MOUNTING MEANS ADAPTED TO MOUNT THE SUPPORT MEANS FIRMLY ON THE BLADE MEMBER FOR MOVEMENT THEREWITH, AN ELONGATED ELECTRICALLY CONDUCTIVE CABLE MOUNTED ON THE SUPPORT FOR EXTENSION AND RETRACTION RELATIVE TO THE LATTER, ELECTRICALLY CONDUCTIVE MEANS OPERATIVELY ENGAGING THE CABLE AND ADAPTED FOR ENGAGING THE BLADE MEMBER FOR ELECTRICALLY INTERCONNECTING THE CABLE AND BLADE MEMBER, RESILIENT MEANS OPERATIVELY INTERENGAGING THE ABLE AND SUPPORT FOR URGING THE CABLE IN THE RETRACTING DIRECTION, ELECTRICALLY CONDUCTIVE TERMINAL MEANS ON THE EXTENDABLE END OF THE CABLE, AND ELECTRICALLY CONDUCTIVE RETAINER MEANS DISPOSED 